redis Distributed Lock

src/main/java/com/zeekling/redis/lock/DistributedLock.java

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+package com.zeekling.redis.lock;
+
+/**
+ * 实现的分布式锁
+ */
+public interface DistributedLock {
+
+  /**
+   * 获取锁
+   *
+   * @return 锁的标识
+   */
+  String lock();
+
+  /**
+   * 通过锁的标识释放锁
+   *
+   * @param identify 唯一标识
+   * @return 释放锁是否成功
+   */
+  boolean unlock(String identify);
+
+}

src/main/java/com/zeekling/redis/lock/RedisDistributedLockImpl.java

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+package com.zeekling.redis.lock;
+
+import redis.clients.jedis.JedisCluster;
+import redis.clients.jedis.params.SetParams;
+
+import java.util.Collections;
+
+/**
+ * 基于Redis实现的分布式锁
+ */
+public class RedisDistributedLockImpl implements DistributedLock {
+
+
+  private static final String LOCK_SUCCESS = "OK";
+
+  private static final Long UNLOCK_SUCCESS = 1L;
+
+  //
+  private static final String UNLOCK_SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
+
+  private final JedisCluster cluster;
+
+  private final long lockTimeout;
+
+  private final String lockKey;
+
+  public RedisDistributedLockImpl(JedisCluster cluster, String lockKey, long lockTimeout) {
+
+    this.cluster = cluster;
+    this.lockTimeout = lockTimeout;
+    this.lockKey = lockKey;
+  }
+
+  @Override
+  public String lock() {
+    long end = System.currentTimeMillis() + lockTimeout;
+    String requireToken = String.valueOf(System.currentTimeMillis());
+    int expireTime = 300 * 1000;
+    SetParams params = new SetParams().nx().px(expireTime);
+    while (System.currentTimeMillis() < end) {
+      try {
+        String result = cluster.set(lockKey, requireToken, params);
+        if (LOCK_SUCCESS.equals(result)) {
+          System.out.println("lock success");
+          return requireToken;
+        }
+        System.out.println("lock failed trying");
+        Thread.sleep(100);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+      } catch (Exception e) {
+        e.printStackTrace();
+        return null;
+      }
+    }
+    return requireToken;
+  }
+
+  @Override
+  public boolean unlock(String identify) {
+    if (identify == null || identify.trim().length() == 0) {
+      return false;
+    }
+    Object obj = new Object();
+    try {
+      obj = cluster.eval(UNLOCK_SCRIPT, Collections.singletonList(lockKey), Collections.singletonList(identify));
+      if (UNLOCK_SUCCESS.equals(obj)) {
+        System.out.println("release lock success, requestToken:" + identify);
+        return true;
+      }
+    } catch (Exception e) {
+      e.printStackTrace();
+    }
+    System.out.println("release lock failed, requestToken:" + identify + ", result:" + obj);
+    return false;
+  }
+}

src/test/java/com/zeekling/redis/RedisDistributedLockTest.java

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+package com.zeekling.redis;
+
+import com.zeekling.redis.lock.RedisDistributedLockImpl;
+import redis.clients.jedis.HostAndPort;
+import redis.clients.jedis.JedisCluster;
+import redis.clients.jedis.JedisPoolConfig;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class RedisDistributedLockTest {
+
+  static int n = 500;
+
+  public static void secKill() {
+    System.out.println("商品数量：" + --n);
+  }
+
+  public static void main(String[] args) {
+    Runnable runnable = () -> {
+      RedisDistributedLockImpl lock = null;
+      String unLockIdentify = null;
+      try {
+        Set<HostAndPort> set = new HashSet<>();
+        set.add(new HostAndPort("127.0.0.1", 30001));
+        JedisPoolConfig config = new JedisPoolConfig();
+        JedisCluster cluster = new JedisCluster(set, config);
+        lock = new RedisDistributedLockImpl(cluster, "test1", 20000);
+        unLockIdentify = lock.lock();
+        System.out.println(Thread.currentThread().getName() + "正在运行");
+        secKill();
+      } finally {
+        if (lock != null) {
+          lock.unlock(unLockIdentify);
+        }
+      }
+    };
+    System.out.println("------------------开始--------------");
+    for (int i = 0; i < 100; i++) {
+      Thread t = new Thread(runnable);
+      t.start();
+    }
+  }
+
+}